This invention relates to a method for manufacturing filters in which a filter material in the form of a continuous web is folded in a zig-zag manner in order to produce pleats in a resulting pleated filter element.
Published European Patent Application No. EP 260,267 B1 discloses a method in which filter material in the form of a continuous web is folded zig-zag to form pleats as a filter element. These pleats are fed on a transport medium, e.g., a conveyor belt, to a transport screw where the precise pleat spacing is set, and then the filter is sealed at its lateral edges.
A disadvantage of this known method is to be seen in the fact that the filter element can only take simple geometrical shapes. Especially in the production of air filters for passenger compartment ventilation in motor vehicles, it is necessary, as a result of the constricted space available, to create complex geometrical shapes for optimum adaptation to the surrounding area.
It is already known to create geometrical shapes in which, for example, a corner is clipped. This alone, however, does not suffice to produce complex geometrical shapes needed to make optimum use of the limited space available for the housing surrounding the filter.